Iván Palomo. Departamento de
Bioquímica Clínica e Inmunohematología, Facultad de Ciencias de la Salud. Universidad de Talca, Talca, Chile. Casilla 747,Talca, Chile.Factor V Leiden and G20210A mutation of
prothrombin gene are two important genetic polymorphisms associated with an increased risk for
thrombosis. Aim: To establish the prevalence of factor V Leiden and prothrombin G20210A mutation
in the Chilean population and their association to venous and arterial thromboembolism. Material
and methods: A case-control study was conducted where 149 patients with thrombosis (87 with
arterial and 62 with venous thrombosis) confirmed by CAT-scan, electrocardiogram and cardiac
enzymes or Doppler depending on the case, and 160 healthy blood donors were genetically analyzed
for the presence of both polymorphisms. Results: Factor V Leiden mutation was found in 5.4% of
patients and in 1.3% of healthy controls (p=0.04). Heterozygosity for G20210A prothrombin mutation
was found in 5.4% of patients and in 2.5% of the control group (p=NS). When arterial and venous
thrombosis were considered as separate entities, 4.6% of patients with arterial thrombosis and 6.5%
with venous thrombosis presented factor V Leiden (p=NS). Likewise, 8.1% of patients with venous
thrombosis and 3.5% of patients with arterial thrombosis had G20210A prothrombin mutation
(p=NS). Conclusions: In non selected consecutive Chilean patients with arterial and venous
thrombosis the frequency of factor V Leiden and prothrombin G20210A is less than we could expect
from their prevalence in the general populatio
